That would have been a bizarre decision.
Katko should be vulnerable anyway, though, right?
In theory, yeah it's a seat that the dems have to contest but Katko just won Onondaga County 57 - 43 at the same time that Clinton won it 54 - 40. And that's not even counting the more conservative counties in the district (Cayuga, Wayne, Oswego). So Katko had a pretty strong grip on the mythical swing voters. Maybe the dems could do better with a candidate who's argument is stronger than "Hey guys Kirsten Gillibrand wants you to vote for me!" Trump's disapproval could help too. The problem is that this district also has a history of abysmal dem turnout in midterms.